Jason Liu attended the 2017 Workshop on Modeling & Simulation of Systems and Applications, August 09-11, 2017, held at the University of Washington, Seattle, WA, USA. The three-day workshop is organized by Adolfy Hoisie (PNNL) and provided a DOE-centric perspective on HPC modeling and simulation. In particular, the workshop explored the impact of modeling and simulation on the traditional HPC and its potential on new computing paradigms in the era of exascale computing.